Above ground fluid storage system

ABSTRACT

An above ground liquid storage system includes a substantially impermeable liner bounding an interior for receiving a liquid. A plurality of supporting structures and a base support the liner and the liquid when the liquid is received in the interior. The liner extends from the base over a top end of the plurality of supporting structures and descends to the ground to form a cavity under the plurality of supporting structures. A temperature controller in communication with the cavity controls a temperature of the cavity to control the temperature of liquid in the interior.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No. 61/474,431 filed Apr. 12, 2011, the entire disclosure of which is incorporated herein by reference.

TECHNICAL FIELD

This invention relates, in general, to storage systems for holding large quantities of various fluids for use in industrial, commercial and energy applications, and more particularly systems for above ground impoundment of water for use in a hydraulic fracturing process.

BACKGROUND ART

Hydraulic Fracturing (i.e., fracking) is a method of extracting natural gas that is trapped in the layers of shale thousands of feet below the surface. The process involves drilling into shale formations (5,000 to 20,000 feet below the surface) and pumping fracturing fluid into the formation at great pressures fracturing the rock creating a conduit for the natural gas to be extracted through. The fracking process requires millions of gallons of water, much of which is extracted from the shale formations and must be stored prior to being treated for any contaminants which they receive during the drilling process. Most “fracking” sites in the Marcellus Shale region located in Pennsylvania, West Virginia, and southern New York are in very remote locations and the pads (drilling sites) have relatively small footprints, thus the storage of massive amounts of water within a small footprint requires a voluminous vessel. Currently there are two methods for large water storage: below ground (lined pit) and above ground (defined storage vessel).

Thus, a need exists for systems and methods for storing liquids above ground which are intended to be used for, or have been extracted from, drilling sites. These systems and methods may be utilized in remote locations and may protect the environment.

SUMMARY OF THE INVENTION

The present invention provides, in a first aspect, an above ground liquid storage system which includes a substantially impermeable liner bounding an interior for receiving a liquid. A plurality of supporting structures and a base support the liner and the liquid when the liquid is received in the interior. The liner extends from the base over a top end of the plurality of supporting structures and descends to the ground to form a cavity under the plurality of supporting structures. A temperature controller in communication with the cavity controls a temperature of the cavity to control the temperature of liquid in the interior.

The present invention provides, in a second aspect, a method for use in above ground storage of a liquid which includes connecting a plurality of supporting structures to one another such that a base is surrounded by the plurality of supporting structures. A liner is located on the base and the plurality of supporting structures such that the liner extends from the base over a top end of the plurality of supporting structures and descends to the ground to form a cavity under the plurality of supporting structures. A liquid is received in a cavity bounded by the liner. A temperature of the cavity is controlled to control the temperature of the liquid.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention will be readily understood from the following detailed description of preferred embodiments taken in conjunction with the accompanying drawings in which:

FIG. 1 is a cutaway view of a portion of a supporting system supporting a basin in accordance with the present invention;

FIG. 2 is a side cross-sectional view of the basin of FIG. 1;

FIG. 3 is a perspective view of a backside of the supporting system of the basin of FIG. 1;

FIG. 4 is a perspective view of the basin of FIG. 1;

FIG. 5 is a side cross-sectional view of a portion of the basin of FIG. 1 including an air conditioning mechanism and fluid connection means connected to an underside of the basin;

FIG. 6 is a side view of a clamp for connecting the supporting structures of the basin of FIG. 1 to each other;

FIG. 7 is a front view of the clamp of FIG. 6 including a cover in accordance with the present invention; and

FIG. 8 is a perspective view of the basin of FIG. 1 including a conduit on a support member allowing fluid flow over a top side of the basin.

DETAILED DESCRIPTION

In an exemplary embodiment depicted in FIGS. 1-7 an above ground liquid containment system or basin 51 is shown. Basin 51 may be configured (e.g., shaped and dimensioned) to any shape and various heights. Basin 51 may include a series of interconnected supporting structures or frame units 100 spaced at intervals erected on a prepared surface (e.g., a concrete pad) to form a container skeleton or support structure. Each frame unit includes a support portion 30 and a leg portion 40 facing an interior 50 of the basin. A plurality of leg portions 40 may extend upwardly at an angle (e.g., about 43 degrees) to support basin 51 and any contents of interior 50. The leg portions may be supported by a plurality of support portions 30. The support portions and leg portions may be formed of wood, metal or plastic members fastened to each other and configured to carry the weight of a liquid (e.g., water from a fracturing process) in interior 50 of basin 51. Such support portion and leg portions could also be monolithically formed (e.g., by molding, casting, etc.). As depicted in the figures, such a leg portion (e.g., leg portion 40) may have a linear shape extending from base 70 at an angle less than 90 degrees and more than 30 degrees, for example, while the support portion (e.g., support portion 30) may be formed of a V shaped structure having a bottom horizontal portion 31 and a side portion extending from an end of horizontal portion 31 (i.e., the end away from base 70) to contact leg portion 40. A frame cavity 60 (e.g., having a triangular shape) may be formed by the connection of one of support portions 30 to one of leg portions 40. The cavity may be a variety of shapes (e.g., an equilateral triangle) depending on the configuration (e.g., shape and dimension) of the support portions and leg portions.

A thick geogrid material 20 may extend from a top 41 of each leg portion 40 downwardly on the leg portion and continue a short distance out onto a base 70 as depicted in FIG. 1, for example. Geogrid material 20 has the ability to restrict a liner 80 from forming pockets within frame units 100 due to the added rigidity it provides, thus keeping a surface of the liner facing the liquid as a smooth sided container. Geogrid material 20 is attached at intervals to one or more of support portions 30 and/or leg portions 40 of the frame unit with zip ties or other connection mechanism(s). Geo-grid material 20 may be a material configured for use as a base course for reinforcement and soil stabilization such as MARAFI BXG GEOGRID. Such a geo-grid material may have a tensile strength of 2,500 pounds per foot in a machine direction and 2,500 pounds per foot in a cross direction.

Base 70 (i.e., horizontal portion surrounded by the frame units) of basin 51 may be a portion of a concrete pad or other material capable of supporting the weight of liquid thereon in conjunction with the frames (e.g., frames 100) which surround such base. Further, basin 51 may be lined with a thick felt material 22 which overlaps geogrid material 20 a short distance and is attached to one or more of support portions 30 and/or leg portions 40 by means of zip ties or other connection mechanism(s). For example, the felt may be a needle punched non-woven geo-textile composed of polypropylene fibers formed with a stable network such that the fibers retain their relative position, such as MIRAFI 180N. Such a geo-textile may be inert to biological degradation and resist naturally encountered chemicals, alkalis and acids. The felt material 20 may have a weight of 271 grams per meter squared and a thickness of 1.8 mm, for example.

Liner 80 may be a continuous liner impermeable to liquids (e.g., water) installed on the container skeleton (i.e., frame units 100, geogrid material 20, base 70). Liner 80 may be tailored (e.g., shaped and dimensioned) to fit the inside measurements of basin 51 (e.g., the inside surface of the plurality of leg portions 40 and base 70) and extend over the top (e.g., top 41) of frame units 100 and vertically down to the ground on the outside of the container, where it may be anchored to the ground by weight. FIGS. 4 and 5 depict the liner pulled over the frame to the ground. Further, the liner may be any type of liner which may support the weight of water or another liquid when connected to frame units 100 and may be substantially impermeable. Also, liner 80 may be formed of a plurality of liner portions welded or otherwise connected to one another such that the seams are substantially impermeable. Further, liner 80 could be formed of a scrim reinforced polyethylene, such as DUR SKRIM. Such a liner could have an average thickness of about 30 mil, a weight of about 144 pounds per thousand square feet. The liner may also have a tensile strength of 160 foot pounds per square inch in a machine direction and 150 foot pounds per square inch in a transverse direction. The liner may be a reinforced laminate manufactured using high strength virgin grade polyethylene resins and stabilizers.

When liner 80 extends from top 41 to the ground, a liner cavity or area 81 under liner 80 and under leg portions 40, including cavities 60, may be heated, cooled or otherwise conditioned. For example, warmed air may be pumped into area 81 to maintain the area under leg portions 40 at a desired temperature such that any liquid held in interior 50 is held at a desired temperature due to the convection and conduction occurring in the area under leg portions 40 relative to leg portions 40, geogrid 20, any felt and liner 80. For example, area 81 under leg portions and under liner 80 (e.g., including cavities 60) may be heated (e.g., a heater 3 may be connected to a tube 4 to provide heated air as depicted in FIG. 7) to avoid any liquid in interior 50 from freezing thereby avoiding any damage that could occur to liner 80 resulting from freezing and/or thawing of the liquid. Also, a bubbling mechanism 11 may be utilized to inhibit freezing of the liquid in basin 50 to minimize any such damage to liner 80 as depicted in FIG. 7. Such a bubbling mechanism could be any type of air generating mechanism which provides air to a liquid held in interior 50 to inhibit freezing of the liquid and thereby avoid any damage to basin 51, including liner 80, due to such freezing.

Basin 51 could also be configured to include under-floor or over-top piping to accommodate inflow/outflow requirements into and/or out of interior 50. Over the top piping may be utilized where under-floor piping is not feasible, for example. Basin 51 could also be configured to allow the liquid/slurry to weir over in a particular location at a desired elevation. As depicted in FIG. 5, a drain/inlet may be provided in base 70 and liner 80 to allow fluid communication therethrough. As depicted in the figures, fluid communication may be provided through an underside (e.g., base 70) of basin 51. A manhole casting 5 may connect to an underside of basin 51 opposite interior 50 and seals 6 may be utilized on opposite sides of liner 80. A manhole riser 7 may be coupled to casting 5 and the seals. A conduit 8 may connect riser 7 to a manifold system 10 to allow the introduction and/or removal of liquids relative to interior 50 therethrough. A shutoff valve 9 may be utilized to allow or prevent such fluid communication.

In one example, manhole casting 5 may be 6″ to 8″ in height. The drain may be 24″ in diameter on top (for the opening) and then 36″ at the base which is between 5′ and 7′ below the top surface of the drain. These dimensions may be adjusted as desired, e.g., to adjust an amount of flow to fill and discharge the system.

As depicted in FIGS. 6 and 7, a clamp cover 150 may protect the liner material (i.e., liner 80) from a clamp. The cover may be formed of a foam material (e.g., 1.7# low density form fit polyethylene foam or any other material which would properly act as a cushion/buffer to minimize risk of damage from impact, chaffing, puncturing or tearing) which fits over a clamp 160 which then rests against the geogrid material (e.g., geogrid material 20), which contacts the liner material. The cover may be connected to the clamp by twine or zip ties, for example. Multiple clamps 160 may be utilized to connect individual frame units (e.g., units 100) to each other as depicted in the figures. For example, a top portion 153 and a bottom portion 154 may receive multiple leg portions 40 therebetween to connect such leg portions to one another. The top portion and bottom portion could be connected to each other by a fastening mechanism, such as a bolt 155, for example. Clamp 160 could be shaped and dimensioned in any way to allow adjacent frame units 100 (e.g., leg portions 40 thereof) to be connected to one another.

Further, basin 51 may include a portion thereof having a top end lower than a remaining portion of such basin. For example, several of frame units 100 may include leg portion 40 of reduced length such that a top end in the local area of such reduced dimensioned leg portions are lower than the top ends of other leg portions adjacent such reduced dimension leg portions. This reduced height may form a weir to allow liquid in interior 50 to flow out of basin 51 when such liquid reaches a top end of the reduced height portion. Such a “weir over” arrangement may be useful in the case of the subsurface conditions don't allow for a underground method or when such an underground method is not cost effective.

In another example, basin 51 may include a conduit 200 which extends from liner 80 in the vicinity of top end 41 into interior 50 and rests on a supporting surface, such as concrete blocks 210, as depicted in FIG. 8. Such blocks may act as an anchoring point for the conduit and also may act as a diffusion device when fluid flows at high velocity through conduit 200. Liquid may flow into and/or out of basin 51 through conduit 200 (e.g., via pump(s)). A support 220 may extend from one of blocks 210 to a position at/or near top end 41 to support conduit 200 as depicted in FIG. 8.

Further, in another example, through-wall piping for filling/evacuating fluid materials may be used when sub-surface conditions don't permit installation of an in-floor system (e.g., conduit 8) or an over-the-top system cannot be properly stabilized (e.g., secured to dead-men inside basin) to minimize the risk of liner damage by pipe thrashing. Such a through-wall piping system would extend through leg 40, liner 80, and geo-grid 20, for example, such that a conduit extending through leg 40, and liner 80 is sealed to inhibit leakage through liner 80 and leg 40 other than that flowing through such conduit.

The above described system (e.g., basin 51) may be used for the temporary short or long term storage of any form of liquid or slurry where in-ground impoundments or frack tanks are either not permitted or not viable. Such systems are intended to be used above ground and are portable; the frame units and separate hardware can be individually stacked and transported by truck to any location including very remote locations. The systems may be easily assembled, broken down and re-assembled at different locations. For example, each of frames 100 may be releasably connected to adjacent frames of frames 100 to form the structure of basin 51 by a plurality of clamps (e.g., clamp 150) and/or other connecting mechanism (e.g., cables) thereby allowing a basin to be constructed in various sizes and shapes (e.g., by using different number of frames 100 in different configurations) and allowing the easy deconstruction and movement of such a basin from one place to another due to the releasable nature of the connections. The frames may also be separated from each other and re-used after a basin has achieved a particular purpose, for example. The assembly and re-assembly may be done by hand with the assistance of lifting machinery. The system (e.g., basin 51) may be used for central frack water storage in the Marcellus shale industry in Pennsylvania where limited access is available, for example. It may also be used for many other types of storage requirements. Basin 51 would not affect the existing water table and has a minimal impact on the ground and surrounding area where it is being used due to its above ground construction.

Further, basin 51 may permit temporary storage of millions of gallons of fresh water used in industrial, commercial and energy applications. Basin 51 may be ten feet high, for example, providing a larger storage capacity when compared to similar above ground systems. The described systems may be portable and may be assembled, broken down re-located and re-assembled in a minimal time-frame as compared to similar above ground systems as described above.

Basin 51 may be completely modular and can be constructed into any shape or size configuration based on needs (e.g., maximizing the drill pad footprint) of a user. The system described (e.g., basin 51) may have in-floor or thru-wall piping capabilities for quick fill and discharge requirements. The system described (e.g., basin 51) may have minimal labor and equipment requirements for assembly/disassembly. Further, the system described (e.g., basin 51) is environmentally friendly and requires minimal disturbance/impact to terrain.

While the invention has been depicted and described in detail herein, it will be apparent to those skilled in the relevant art that various modifications, additions, substitutions and the like can be made without departing from the spirit of the invention and these are therefore considered to be within the scope of the invention as defined in the following claims. 

1. An above ground liquid storage system comprising: a substantially impermeable liner bounding an interior for receiving a liquid; a plurality of supporting structures and a base supporting the liner and the liquid when the liquid is received in said interior; said liner extending from said base over a top end of said plurality of supporting structures and descending to the ground to form a cavity under said plurality of supporting structures; and a temperature controller in communication with said cavity and controlling a temperature of said cavity to control a temperature of the liquid in said interior.
 2. The system of claim 1 further comprising a freeze inhibiting mechanism coupled to the liquid in the interior for providing gas bubbles or sufficient agitation to the liquid to inhibit freezing of the liquid.
 3. The system of claim 1 further comprising an opening in said base connected to a conduit, said conduit and opening allowing fluid communication between said interior and an exterior opposite said plurality of supporting structures relative to said interior.
 4. The system of claim 1 further comprising a weir over portion to promote flow of the liquid in said interior over said plurality of supporting structures.
 5. The system of claim 4 wherein said weir over portion comprises a plurality of weir supporting structures connected to said plurality of supporting structures and having a weir top end having a height less than said top end.
 6. The system of claim 1 wherein each supporting structure of said plurality of supporting structures is connected to each adjacent supporting structure of said plurality of supporting structures by at least one clamp, said at least one clamp covered by a clamp cover located between said clamp and said liner to inhibit damage to said liner from said clamp.
 7. A method for use in storing a liquid comprising: connecting a plurality of supporting structures to one another such that a base is surrounded by the plurality of supporting structures; locating a liner on the base and the plurality of supporting structures such that the liner extends from the base over a top end of the plurality of supporting structures and descends to the ground to form a cavity under the plurality of supporting structures; receiving a liquid in an interior bounded by the liner; and controlling a temperature of the cavity to control a temperature of the liquid in the interior.
 8. The method of claim 7 further comprising coupling a freeze inhibiting mechanism to the liquid in the interior and providing gas bubbles or sufficient agitation to the liquid to inhibit freezing of the liquid.
 9. The method of claim 7 further comprising providing fluid communication between the interior and an exterior opposite the plurality of supporting structures relative to the interior through an opening in the base connected to a conduit located under the base.
 10. The method of claim 7 further comprising allowing a flow of the liquid over a lowered portion of the plurality of supporting structures, the lowered portion comprising a plurality of weir supporting structures having a top end lower than the top end of the plurality of supporting structures.
 11. The method of claim 7 further comprising clamping the plurality of supporting structures to each other via at least one clamp, wherein the at least one clamp is covered by a clamp cover located between the clamp and the liner to inhibit damage to the liner from the clamp. 